Photographic shutter.



.No. 722,449. PATENTED MAR. 10, 1903.

L. J. R. HOLST.

PHOT'OGRAPHIG SHUTTER.

APPLIOATIOF.I'ILED JUNE 6, 1901.

big); //E\W gkb UNITED STATES PATENT OFFICE.

LODEWYK J. R. HOLST, OF BROOKLYN, NEW YORK, ASSIGNOR OF TWO- THIRDS TOLOUIS BORSUM, OF PLAINFIEL D, NEW JERSEY.

PHOTOGRAPHIC SHUTTER.

SPECIFICATION forming part of Letters Patent N 0. 722,449, dated March10, 1 903.-

Application filed June 6, 1901.

To all whom it may concern.-

Be it known that I, LODEWYK J AN RUTGER HoLsT, a subject of the Queen ofthe Netherlands, (but having declared my intention of becoming a citizenof the United States and having taken out my first naturalizationpapers,) residing in the borough of Brooklyn, city of New York, State ofNew York, have invented certain new and useful Improvements inPhotographic Shutters, of which the following is a specification.

This invention relates to focal-plane shutters. Its object is to effectadjustment of the slit between the curtain-sections from the exterior ofthe shutter-frame or camera-box without the use of extra rollers orspindles. To that end I connect both ends of each curtain-section withits roller in such manner that while the shutter may be actuated in theusual way the slit may be adjusted by the rotation of one or'bothrolls.

In the accompanying drawings, Figure 1 is a transverse vertical sectionthrough a camerabox, showing a shutter mounted and adapted to beoperated in accordance with my invention; Fig. 2, a detail longitudinalsection on the line 2 2 of Fig. 1, and Fig. 3 a detail side elevation.

A B are the two curtain-sections, the adjacent free edges of which arestiffened by rods a b in the usual way.

A is the roll of section A; B, the roll of section B. From each end ofthe stiffening rod or strip 1) a cord or tape 0 passes over the roll Ain the same direction in which its curtainsection is wound upon it andpasses thence around the roller B in a direction opposite that in whichits curtain-section is wound thereon. A suitable seat or annular grooveis formed upon the roll A to receive the cord 0, while the part of theroll B around which the cord passes and to which its end is attached ispreferably formed as a flanged tapered drum, (marked O.) Similarly eachcorner of the free end of the curtain-section O has attached to it acord or tape D, which passes over the roll B, thence to and around adrum D on the roll A. The spindle E of the roll A has at one end apulley e to receive a belt E, that passes over a similar pulley e on theroll B.

It is obvious that when either Serial No. 63.397. (N0 model.)

roller is rotating in a direction to unroll the curtain from it it wouldequally roll up the cords or tapes, and thereby keep the curtain taut atall times. When one roller is rotated independently of the other, therewill necessarily be a change in the width of the slit or opening betweenthe rods 64 b. This independent motion may be obtained by constructingin the manner presently described or otherwise one of the rollers,preferably the upper one, or that upon which the curtain or shutter iswound in setting it, the lower or other roll being, as usual,"thespringroll. The other end of the spindle E extends through the cameraboxor shutter-frame, having its bearing in a sleeve F, integral with theroll A, as are also the parts D and the core pieces or plugs ff, inwhichthe spindle is also seated. On the projecting end of the sleeve Fis a disk G, having in it a series of apertures g, equally distant fromthe axis of the sleeve, andon the projecting end of the spindle is aknob H and an arm it, having thereon a pin adapted to engage theapertures As shown, the spindle is divided and lap-jointed, as indicatedat 00, so as to allow a slight endwise movement of its projectingknobbed end, which is limited by a stop-pin 00 in the movable section ofthe spindle, the purpose being to permit of the disengagement of the armh from the diskG, V The same result, however, may be accomplished bymaking the arm h sufficiently resilient to permit of itsbeing drawn backto disengage the pin thereon from the disk.

The general arrangement andconnection of the curtainsections isimportant. The mere details of the roller and spindle construction areunimportant.

When the spindle E and disk Gare locked together, both curtain-sectionsof the shutter will act in unison in the ordinary way; but whendisengaged the roll and spindle can be rotated independently, therebyefiecting a variation of the width of the slit or opening between theedges of the curtain-sections. If the spindle when disconnected from thedisk G is rotated, the roll B will, by means of the belt E, be rotatedand the edge I) of its curtain-section will be advanced or withdrawnfrom the edge of the curtain-section A.

If the spindle be held stationary and the disk G rotated whiledisengaged from it, a similar movement of the curtain A will beeffected. The construction described permits of the regulation of thewidth of the slit to any desired extent either before or after theshutter is set for action. The knob E and disk G may be employed to setthe shutter by winding it upon the roll A.

The shutter may be tripped in any usual and suitable way. For instance,the usual ratchet or toothed wheel may be placed upon the roll A ateither side within the camerabox to cooperate with the ordinary latchthat may be tripped in any way. As shown in the drawings, the peripheryof the disk G is formed with teeth which are engaged by a latch K,mounted on the-outside of the camera-box. This latch may be tripped bydirect application of the hand by a pneumatic bulb or otherwise. Theplan that may be adopted for locking the roll A when the curtain iswound upon it and the manner of releasing it to permit the actuation ofthe shutter are quite immaterial, and the devices may be arranged withinor without the camera-box, as may be desired.

I claim as my invention 1. A photographic focal-plane shutter comprisingtwo curtains, the rolls to which they are connected, separateconnections between both ends of each curtain and its roll, whichconnections are wound in a reverse direction around the roll of thecurtain to which it is attached, and means for actuating a roll to Varythe slit between the two curtain-sections.

2. A photographic focal-plane shutter comprising two curtain-sections,their respective rolls, separate flexible connections between the freeends of each curtain-section and its roll, which connections pass in areverse direction around the roll of the curtain to which it is attachedand which also pass around the other roll, and means for actuating aroll to adjust the slit between the two curtain-sections.

3. A photographic focal-plane shutter comprising two curtain-sections,their respective rolls, flexible connections between the free ends ofeach curtain-section and its rolls, which connections are wound inreverse direction around the roll of the curtain t which they areattached, and which also pass around the other roll, and means forrevolving one roll independently of the other to adjust the slit betweenthe two curtain-sections.

4. A photographic focal-plane shutter,comprising two curtain-sections,their respective rolls, a belt connection between them to insure theirnormal conjoint rotation, flexible connections between either end ofeach curtain-section and its roll, which connections are wound inreverse direction to the roll of the curtain to which they are attached,and which pass around the other roll, and means for actuating a roll toadjust the slit between the curtain-sections.

5. A photographic focal-plane shutter comprising two curtain-sections,their respective rolls, means for disconnecting one roll from itsspindle to permit of rotation of either roll or spindle, a drivingconnection between said spindle and the other roll, and flexibleconnections between the free ends of each curtain-section and its roll,which connections are wound in a reverse direction about the roll of thecurtain to which it is attached, and which are also wound around theother roll.

In testimony whereof I have hereunto subscribed my name.

L. J. R. I-IOLST.

Witnesses:

KATHARINE MAOMAHON, EDWARD C. DAVIDSON.

